The Germans invaded the Soviet Union in 1941. Leaders of the SS and police and leaders of the German armed forces had concluded pre-invasion agreements. In accordance with these agreements, SS and police units—including Einsatzgruppen of the German Security Police and SD and battalions of the German Order Police—followed German troops into newly occupied Soviet territory. Acting as mobile killing units, they conducted shooting operations aimed at annihilating entire Jewish communities. By autumn 1941, the SS and police introduced mobile gas vans. These paneled trucks had exhaust pipes reconfigured to pump poisonous carbon monoxide gas into sealed spaces, killing those locked within. They were designed to complement ongoing shooting operations.
The men selected April 15, the darkest night of the month, for the escape. Dogim, the unofficial leader of the group, was first—once he emerged from the tunnel, he would cut a hole in the nearby fence and mark it with a white cloth, so the others would know which direction to run. Farber was second. Motke Zeidel was sixth. The prisoners knew that a group of partisan fighters were holed up nearby, in the Rudnitsky Woods, in a secret camp from which they launched attacks on the Nazi occupiers. “Remember, there is no going back under any circumstances,” Farber reminded his friends. “It is better to die fighting, so just keep moving forward.”
Mengele was born on 16 March 1911 to Walburga (née Hupfauer) and Karl Mengele in Günzburg, Bavaria, Germany. He was the oldest of three children; his two younger brothers were Karl Jr. and Alois. Their father was founder of the Karl Mengele & Sons company, producers of farm machinery. Josef was successful at school and developed an interest in music, art, and skiing. He completed high school in April 1930 and went on to study philosophy in Munich, where the headquarters of the Nazi Party were located. In 1931, Mengele joined the Stahlhelm, Bund der Frontsoldaten, a paramilitary organization that was absorbed into the Nazi Sturmabteilung (Storm Detachment; SA) in 1934.